Buggy code:
private int headerEndPosition = - 1 ; private FormatterCommentParser formatterCommentParser ; Scribe ( CodeFormatterVisitor formatter , long sourceLevel , IRegion [ ] regions , CodeSnippetParsingUtil codeSnippetParsingUtil , boolean includeComments ) { } private void adaptRegions ( ) { } private final void addDeleteEdit ( int start , int end ) { } public final void addInsertEdit ( int insertPosition , String insertedString ) { } private final void addOptimizedReplaceEdit ( int offset , int length , String replacement ) { } public final void addReplaceEdit ( int start , int end , String replacement ) { } public void alignFragment ( Alignment alignment , int fragmentIndex ) { } public void checkNLSTag ( int sourceStart ) { } public Alignment createAlignment ( String name , int mode , int count , int sourceRestart ) { } public Alignment createAlignment ( String name , int mode , int count , int sourceRestart , boolean adjust ) { } public Alignment createAlignment ( String name , int mode , int tieBreakRule , int count , int sourceRestart ) { } public Alignment createAlignment ( String name , int mode , int count , int sourceRestart , int continuationIndent , boolean adjust ) { } public Alignment createAlignment ( String name , int mode , int tieBreakRule , int count , int sourceRestart , int continuationIndent , boolean adjust ) { } public Alignment createMemberAlignment ( String name , int mode , int count , int sourceRestart ) { } public void enterAlignment ( Alignment alignment ) { } public void enterMemberAlignment ( Alignment alignment ) { } public void exitAlignment ( Alignment alignment , boolean discardAlignment ) { } public void exitMemberAlignment ( Alignment alignment ) { } public Alignment getAlignment ( String name ) { } public int getColumnIndentationLevel ( ) { } public final int getCommentIndex ( int position ) { } private IRegion getCoveringRegion ( int offset , int end ) { } private int getCurrentCommentOffset ( int start ) { } public String getEmptyLines ( int linesNumber ) { } private int getIndexOfRegionAt ( int offset ) { } public OptimizedReplaceEdit getLastEdit ( ) { } public final int getLineEnd ( int lineNumber ) { } Alignment getMemberAlignment ( ) { } public String getNewLine ( ) { } public int getNextIndentationLevel ( int someColumn ) { } private String getPreserveEmptyLines ( int count ) { } private IRegion getRegionAt ( int offset ) { } public TextEdit getRootEdit ( ) { } public void handleLineTooLong ( ) { } private boolean hasNLSTag ( int sourceStart ) { } private boolean includesBlockComments ( ) { } private boolean includesJavadocComments ( ) { } private boolean includesLineComments ( ) { } boolean includesComments ( ) { } public void indent ( ) { } public void initializeScanner ( char [ ] compilationUnitSource ) { } private void initFormatterCommentParser ( ) { } private boolean isAdaptableRegion ( int offset , int length ) { } private boolean isOnFirstColumn ( int start ) { } private boolean isValidEdit ( OptimizedReplaceEdit edit ) { } private void preserveEmptyLines ( int count , int insertPosition ) { } private void print ( int length , boolean considerSpaceIfAny ) { } private void printBlockComment ( boolean isJavadoc ) { } private void printBlockComment ( int currentTokenStartPosition , int currentTokenEndPosition ) { } private void printBlockCommentHeaderLine ( StringBuffer buffer ) { } public void printEndOfCompilationUnit ( ) { } private void printCodeSnippet ( int startPosition , int endPosition ) { } void printComment ( ) { } void printComment ( int kind ) { } void printComment ( int kind , String source , int start , int end , int level ) { } private void printLineComment ( ) { } private void printLineComment ( int commentStart , int commentEnd ) { int firstColumn = this . column ; int indentLevel = this . indentationLevel ; int indentations = this . numberOfIndentations ; <START_BUG> this . indentationLevel = ( ( this . column ) // ( this . tabLength ) ) * ( this . tabLength ) ; <END_BUG> this . numberOfIndentations = ( this . indentationLevel ) // ( this . indentationSize ) ; this . scanner . resetTo ( commentStart , commentEnd ) ; StringBuffer buffer = new StringBuffer ( ) ; this . scanner . getNextChar ( ) ; buffer . append ( this . scanner . currentCharacter ) ; this . scanner . getNextChar ( ) ; buffer . append ( this . scanner . currentCharacter ) ; this . column += 2 ; StringBuffer tokensBuffer = new StringBuffer ( ) ; boolean bufferHasTokens = false ; int maxColumn = ( this . formatter . preferences . comment_line_length ) + 1 ; int previousToken = - 1 ; int previousPosition = commentStart ; char previousChar = 0 ; boolean firstWord = true ; this . scanner . skipComments = true ; while ( ! ( this . scanner . atEnd ( ) ) ) { int token ; try { token = this . scanner . getNextToken ( ) ; } catch ( InvalidInputException iie ) { if ( ( previousToken == ( - 1 ) ) || ( previousToken == ( TerminalTokens . TokenNameWHITESPACE ) ) ) { tokensBuffer . append ( '<seq2seq4repair_space>' ) ; } this . scanner . resetTo ( this . scanner . startPosition , commentEnd ) ; char ch = ( ( char ) ( this . scanner . getNextChar ( ) ) ) ; previousToken = TerminalTokens . TokenNameWHITESPACE ; while ( ! ( ScannerHelper . isWhitespace ( ch ) ) ) { tokensBuffer . append ( ch ) ; if ( this . scanner . atEnd ( ) ) { previousToken = TerminalTokens . TokenNameEOF ; break ; } ch = ( ( char ) ( this . scanner . getNextChar ( ) ) ) ; } continue ;

Fix:
this . indentationLevel = getNextIndentationLevel ( firstColumn ) ;